diff options
Diffstat (limited to 'include/linux/ipc_namespace.h')
| -rw-r--r-- | include/linux/ipc_namespace.h | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h new file mode 100644 index 000000000..e8240cf26 --- /dev/null +++ b/include/linux/ipc_namespace.h @@ -0,0 +1,213 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __IPC_NAMESPACE_H__ +#define __IPC_NAMESPACE_H__ + +#include <linux/err.h> +#include <linux/idr.h> +#include <linux/rwsem.h> +#include <linux/notifier.h> +#include <linux/nsproxy.h> +#include <linux/ns_common.h> +#include <linux/refcount.h> +#include <linux/rhashtable-types.h> +#include <linux/sysctl.h> +#include <linux/percpu_counter.h> + +struct user_namespace; + +struct ipc_ids { + int in_use; + unsigned short seq; + struct rw_semaphore rwsem; + struct idr ipcs_idr; + int max_idx; + int last_idx; /* For wrap around detection */ +#ifdef CONFIG_CHECKPOINT_RESTORE + int next_id; +#endif + struct rhashtable key_ht; +}; + +struct ipc_namespace { + struct ipc_ids ids[3]; + + int sem_ctls[4]; + int used_sems; + + unsigned int msg_ctlmax; + unsigned int msg_ctlmnb; + unsigned int msg_ctlmni; + struct percpu_counter percpu_msg_bytes; + struct percpu_counter percpu_msg_hdrs; + + size_t shm_ctlmax; + size_t shm_ctlall; + unsigned long shm_tot; + int shm_ctlmni; + /* + * Defines whether IPC_RMID is forced for _all_ shm segments regardless + * of shmctl() + */ + int shm_rmid_forced; + + struct notifier_block ipcns_nb; + + /* The kern_mount of the mqueuefs sb. We take a ref on it */ + struct vfsmount *mq_mnt; + + /* # queues in this ns, protected by mq_lock */ + unsigned int mq_queues_count; + + /* next fields are set through sysctl */ + unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */ + unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */ + unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */ + unsigned int mq_msg_default; + unsigned int mq_msgsize_default; + + struct ctl_table_set mq_set; + struct ctl_table_header *mq_sysctls; + + struct ctl_table_set ipc_set; + struct ctl_table_header *ipc_sysctls; + + /* user_ns which owns the ipc ns */ + struct user_namespace *user_ns; + struct ucounts *ucounts; + + struct llist_node mnt_llist; + + struct ns_common ns; +} __randomize_layout; + +extern struct ipc_namespace init_ipc_ns; +extern spinlock_t mq_lock; + +#ifdef CONFIG_SYSVIPC +extern void shm_destroy_orphaned(struct ipc_namespace *ns); +#else /* CONFIG_SYSVIPC */ +static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} +#endif /* CONFIG_SYSVIPC */ + +#ifdef CONFIG_POSIX_MQUEUE +extern int mq_init_ns(struct ipc_namespace *ns); +/* + * POSIX Message Queue default values: + * + * MIN_*: Lowest value an admin can set the maximum unprivileged limit to + * DFLT_*MAX: Default values for the maximum unprivileged limits + * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply + * an attribute to the open call and the queue must be created + * HARD_*: Highest value the maximums can be set to. These are enforced + * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them + * suitably high) + * + * POSIX Requirements: + * Per app minimum openable message queues - 8. This does not map well + * to the fact that we limit the number of queues on a per namespace + * basis instead of a per app basis. So, make the default high enough + * that no given app should have a hard time opening 8 queues. + * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. + * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, + * we have run into a situation where running applications in the wild + * require this to be at least 5MB, and preferably 10MB, so I set the + * value to 16MB in hopes that this user is the worst of the bunch and + * the new maximum will handle anyone else. I may have to revisit this + * in the future. + */ +#define DFLT_QUEUESMAX 256 +#define MIN_MSGMAX 1 +#define DFLT_MSG 10U +#define DFLT_MSGMAX 10 +#define HARD_MSGMAX 65536 +#define MIN_MSGSIZEMAX 128 +#define DFLT_MSGSIZE 8192U +#define DFLT_MSGSIZEMAX 8192 +#define HARD_MSGSIZEMAX (16*1024*1024) +#else +static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } +#endif + +#if defined(CONFIG_IPC_NS) +extern struct ipc_namespace *copy_ipcs(unsigned long flags, + struct user_namespace *user_ns, struct ipc_namespace *ns); + +static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) +{ + if (ns) + refcount_inc(&ns->ns.count); + return ns; +} + +static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) +{ + if (ns) { + if (refcount_inc_not_zero(&ns->ns.count)) + return ns; + } + + return NULL; +} + +extern void put_ipc_ns(struct ipc_namespace *ns); +#else +static inline struct ipc_namespace *copy_ipcs(unsigned long flags, + struct user_namespace *user_ns, struct ipc_namespace *ns) +{ + if (flags & CLONE_NEWIPC) + return ERR_PTR(-EINVAL); + + return ns; +} + +static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) +{ + return ns; +} + +static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) +{ + return ns; +} + +static inline void put_ipc_ns(struct ipc_namespace *ns) +{ +} +#endif + +#ifdef CONFIG_POSIX_MQUEUE_SYSCTL + +void retire_mq_sysctls(struct ipc_namespace *ns); +bool setup_mq_sysctls(struct ipc_namespace *ns); + +#else /* CONFIG_POSIX_MQUEUE_SYSCTL */ + +static inline void retire_mq_sysctls(struct ipc_namespace *ns) +{ +} + +static inline bool setup_mq_sysctls(struct ipc_namespace *ns) +{ + return true; +} + +#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ + +#ifdef CONFIG_SYSVIPC_SYSCTL + +bool setup_ipc_sysctls(struct ipc_namespace *ns); +void retire_ipc_sysctls(struct ipc_namespace *ns); + +#else /* CONFIG_SYSVIPC_SYSCTL */ + +static inline void retire_ipc_sysctls(struct ipc_namespace *ns) +{ +} + +static inline bool setup_ipc_sysctls(struct ipc_namespace *ns) +{ + return true; +} + +#endif /* CONFIG_SYSVIPC_SYSCTL */ +#endif |